The Special Scientific Procedures Core (Core 3) of the CIDAR center grant application Transdiciplinary Studies of CBT for Anxiety in Youth is responsible for the development, extension, and application of modern state-of-the-art computationally intensive statistical approaches as needed for integrative analysis of data from the Projects. Among other tasks, we propose to: (1) study baseline characteristics across domains and explore the existence of subgroups (clustering); (2) explore the dependence structure of the measures from all projects; (3) examine how subjects' baseline characteristics predict subject trajectories; (4) develop computationally intensive simulation procedures to test proposed mechanisms and models; and (5) develop new methodologies for power studies of those new projects and grant that will arise through the course of this Center.